As I said, Garth Ennis writes Frank Castle mostly as a non-drinker, so if Frank had to drink something called "Long Cold Dark", it might only be a huge pot of cold coffee.But let's expand suspension of disbelief and explore potential drinks.First it seems quite obvious a cocktail with this name should be a long drink, cold (like most of the cocktails) and dark. That last one is the true limiting factor.I might have gone with a rum and coke but that would have been too much of a cheat.But then, I stumbled across some cans of Ginger Beer in an asian shop (Ginger Beer is not very easy to find in France)